Automatic broiler for variable batch cooking

ABSTRACT

A flexible automatic broiler and method of use for variable batch cooking for particular use in quick serve and fast food service restaurants. The automatic cooking devices include a conveyorized cooking surface for alignment and discharge of food products, an altering/pulsating infrared energy radiation heat sources, and a control system. The arrangement and method facilitate a combination of batch preparation and made-to-order assembly of fast-food sandwiches.

FIELD OF THE INVENTION

The present invention relates to automatic broilers for variable batchcooking. The automatic broilers of the present invention have particularuse in quick serve and fast food service restaurants. More particularly,the present invention relates to flexible automatic broilers forbroiling batches of various food products by utilizing a radiant burnerbelow the broiled food product and by altering the infrared energyradiated from a heat source above the broiled food product.

BACKGROUND OF THE INVENTION

Conveyorized chain cooking of various foodstuffs is known in thefast-food industry. Typically, conveyorized chain cooking devicescomprise a continuously moving conveyorized cooking surface displacedadjacent to heating elements. Such conveyorized chain cooking devicesallow for the continuous sequential cooking of food products such asbeef patties and thus accommodate high demand periods in fast foodrestaurants. Conveyorized cooking devices also increase the efficiencyof kitchen operations by uniformly cooking similar food products withoutcontinuous attention from the cook.

Such conveyorized chain cooking devices, however, have significantdisadvantages such as an inability to quickly and efficiently change thecooking profile such that the device is capable of uniformly cooking oneindividual food product or batch of food products and then subsequentlyuniformly cooking a different product or batch of products. For example,conveyorized chain cooking devices have been unable to quickly andefficiently change the thermal output of the heat sources to properlycook different types of meat or different sizes of product.

U.S. Pat. No. 4,924,767 teaches a conveyorized cooking device withvariable-load, low-thermal-mass heating elements to accommodatedifferent food products. These heating elements allow for quick coolingof the cooking zone to prevent burning of subsequently cookedfoodstuffs. Disadvantageously, however, thermal energy is wasted. As aresult of the conveying motion and variable-loads, the heater elementsdo not continuously and uniformly radiate heat directly onto the foodproducts. Further heat is wasted due to the lack of an enclosed cookingarea. Additionally, only electric heating elements are disclosed andthus the problems of providing for varying cooking loads to accommodatedifferent food products using gas burners or flame broiling are notaddressed.

Typical conveyorized cooking devices suffer from additional problems.For example, while such devices allow for continuous sequential cookingof foodstuffs, kitchen operations efficiency is not maximized. Batchloading is not facilitated. Instead, an operator must insert individualproducts at the entry end of the conveyor cooking surface. Additionally,the constant motion of the conveyor cooking surface and the associateddrive train components makes such devices hard to clean, difficult andexpensive to maintain (in terms of parts, labor and downtime) and moresusceptible to breakage. Furthermore, such devices typically do notinvolve a completely enclosed cooking chamber, thus facilitating entryof debris and loss of thermal efficiency.

Still other problems exist with the respect to typical, conventional,control systems. These known control systems, such as thermostats,control temperature regulation in the cooking device. Conventionalcontrols rely on a feed-back loop system that leads to problems,particularly during the cooking process, including inaccurate cookingtemperature and temperature gradients. As a result, the cooked productsmay be undercooked or overcooked, thus reducing the quality of thefinished product. Further, typical cooking devices fail to distinguishbetween different heating stages, such as pre-heat from cold, pre-heatfrom hot, cooking, or idle stages. In addition, typical cooking devicesfail to of maximize the efficiency of the device when operating in thesestages or when transitioning between such stages.

Still further problems exist with control systems associated withconveyorized cooking devices such as the one shown in U.S. Pat. No.4,924,767. There, the cooking device is controlled solely by athermostat device. This results in various problems including inaccuratecooking temperature and temperature gradients leading to a poor qualityfinished product. These problems are compounded by the converyorizednature of the device and its use in a commercial environment. Moreover,the disclosed controller cannot be programmed, cannot conduct a systemcheck or detect system faults, cannot keep track of statistical data,and does not provide audio or visual system status indications.

As the skilled artisan will readily appreciate, there is a differencebetween broiling and baking. Broiling typically requires cookingtemperatures of approximately 500° F. or more. Additionally, broilinginvolves an initial searing action to lock in juices and flavor. As aresult, the cooked product is juicier and more flavorful in addition tohaving an appealing browned outer texture. Baking on the other hand,typically requires cooking temperatures of approximately 450° F. orless. Baking involves cooking without an initial searing action and canlead to a dry and tasteless product with an unappealing texture andcolor.

The desirability of broiled, as opposed to baked, meats compounds manyof the aforementioned problems with conventional conveyorized chaincooking devices. For example, such devices have been unable to quicklyand efficiently change the thermal output of the heat sources toproperly broil meat products in a first instance and then chickenbreasts in a second instance. Similar problems of inflexibility existwhen sequentially cooking batches of meat products, where the individualproducts of one batch differ in size from the individual products in thenext batch, e.g., a batch of large beef patties versus a batch of smallbeef patties. Moreover, when flame broiling is particularly desired,varying the thermal intensity between subsequent batches of food productresults in inefficient operations and losses of thermal efficiencies.

It has therefore been found desirable to provide an automatic dischargebroiler capable of varying the infrared energy radiated at the foodproduct depending on the type of food product and size of the batch tobe broiled while avoiding the aforementioned problems in the prior art.

SUMMARY OF THE INVENTION

The foregoing demonstrates the need for a broiler with varying infraredintensity where the food product is easily loaded and discharged andmethod of use of such a broiler in order to accommodate quickly andefficiently different batches of food products on a menu. Such a broilerand method must also be easy to use and have an associated cost thatallows for incorporation into existing fast-food restaurants.

Therefore, it is an object of the invention to provide a dischargebroiler for batch cooking and method of use that avoids theaforementioned deficiencies of the prior art.

It is another object of the present invention to provide a broiler thatcomprises a conveyorized cooking surface, a lower heat source, a pulsingupper heat source, and a control system for varying the intensity of theinfrared energy emitted from the upper heat source, the control systemalso controlling the cooking time and appropriately actuating theconveyorized cooking surface in accordance with a predetermined cookingprofile.

It is also an object of the present invention to provide a broiler thatincorporates a control unit with predetermined cooking profiles forpre-selected food products, such that the user can select the correctprofile for the desired food product.

It is also an object of the present invention to provide a broiler thatincorporates a control unit to independently activate the upper andlower heating elements, and to allow or prevent the introduction of foodproducts to the broiler depending on broiler status.

It is also an object of the present invention to provide a broiler thatincorporates a control unit to quickly and automatically adjust cookingtemperatures, times, and the cycle of the infrared emitting elements,thereby establishing specific cooking profiles for specific food producttypes.

It is another object of the present invention to provide a broiler thatcomprises a control unit that provides an output signal to indicate thecurrent cooking profile.

It is also an object of the present invention to provide a broiler thatcomprises a control unit that provides an output signal to indicate thestatus of the broiler.

It is also an object of the present invention to provide a broiler thatcomprises a control unit that can store and display statistical dataindicating broiler performance and operating conditions.

It is also an object of the present invention to provide a broiler thatcomprises a control unit that detects various broiler function faultsand provides the ability to diagnose and correct these faults.

It is also an object of the present invention to provide a flexibleautomatic discharge broiler that incorporates a control unit to quicklyand automatically adjust cooking temperatures, times, and the cycle ofthe infrared emitting elements, thereby establishing specific cookingprofiles for specific food product types.

It also an object of the present invention to provide a broiler thatcomprises a housing which increases operating and thermal efficiency.

It is yet another object of the present invention to provide a broilerthat further comprises an opening in the front panel for loading batchesof food product, a second opening in the side panel for dischargingbatches of broiled food product, an automatic door/loading assembly formaintaining thermal boundaries and ensuring proper placement of the foodproduct batches on the conveyorized cooking surface, and furtherprovides a discharge slide for transferring the batches of broiled foodproducts into holding trays.

It is a further object of the invention to provide a method for cookingincluding the steps of loading a batch of food products onto aconveyorized cooking surface, cooking the food products without movingthe conveyorized cooking surface and activating the conveyorized cookingsurface upon completion of the cooking process, such that the foodproducts are discharged.

It is a further object of the invention to provide a method for cookingincluding the steps of loading a batch of food products onto aconveyorized cooking surface, reciprocating the conveyorized cookingsurface during cooking to optimize the food product cooking uniformityand upon completion of the cooking process, activating the conveyorizedcooking surface such that the food products are discharged.

It is a further object of the invention to provide a method for cookingincluding the steps of loading a batch of food products onto aconveyorized cooking surface, laterally adjusting the conveyorizedcooking surface to optimize the cooking position of the food products,cooking the food products without moving the conveyorized cookingsurface, and upon completion of the cooking process, activating theconveyorized cooking surface such that the food products are discharged.

It is a still further object of the invention to provide a method forcooking including the steps of storing a selectable cooking profile inan automatic control means; selecting a cooking profile, loading a batchof food products onto a conveyorized cooking surface, heating the batchof food products with a lower heat source that is below the conveyorizedcooking surface, heating the batch of food product with a variablecontrollably pulsating upper heat source that is above the conveyorizedcooking surface, controlling the thermal output of the upper and lowerheat sources with the automatic control means depending on the cookingprofile selected, and discharging the batch of food products from theconveyorized cooking surface according to the cooking profile selected.

Various other objects, advantages and features of the present inventionwill become readily apparent from the ensuing detailed description andthe novel features will be particularly pointed out in the appendedclaims.

BRIEF DESCRIPTION OF THE DRAWINGS

The following detailed description, given by way of example but notintended to limit the invention solely to the specific embodimentsdescribed, may best be understood in conjunction with the accompanyingdrawings in which:

FIG. 1 is front perspective view of a preferred embodiment of theautomatic broiler of the invention in accordance with the teaching ofthe present invention specifically illustrating various outer componentsthereof;

FIG. 2 is front perspective view of the automatic broiler of FIG. 1 witha discharge slide hood;

FIG. 3 is an isometric view of the automatic broiler of FIG. 1, whichspecifically illustrates various inner components thereof and shows theconveyor assembly in exploded form;

FIG. 4 is an isometric view of the automatic broiler of FIG. 1 with theloading assembly, flame arrestor, and discharge chute in an explodedview;

FIG. 5 is an isometric view of the automatic broiler of FIG. 1specifically illustrating the loading assembly in exploded form;

FIG. 6 is a left side view of the automatic broiler of FIG. 1specifically illustrating the door/loader assembly in the closedposition and the discharge/collection assembly;

FIG. 7 is a left side view of the automatic broiler of FIG. 1specifically illustrating the door/loader assembly in the open positionand the discharge/collection assembly;

FIG. 8 is a front view of the automatic broiler of FIG. 1 specificallyillustrating the control assembly and the discharge/collection assembly;

FIG. 9 is a top view of the automatic broiler of FIG. 1;

FIG. 10 is a sectional view along line D-D of FIG. 9;

FIG. 11 is an enlarged view of the discharge and collection assemblyshown in FIG. 10;

FIG. 12 is a time vs. heat source activation curve for an embodiment ofthe duty cycle mode of operation;

FIG. 13 is a time vs. heat source activation curve for an embodiment ofthe pre-programmed irregular sequence mode of operation;

FIG. 14 is a circuit diagram of an embodiment of the pulsating IRheating elements control system to be used in conjunction with theautomatic broiler of FIG. 1.

FIG. 15 ia a front view of one embodiment of a control mechanismspecifically illustrating an operator input device, a display, andindicator lights.

BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENTS

Turning now more particularly to the drawings, the automatic broiler ofthe present invention has widespread application in the fast-food andquick serve services industry. FIGS. 1 through 13, and 15, illustrateone embodiment of the present invention.

As seen in FIG. 1, automatic broiler 10 generally comprises door/loaderassembly 60, food holding pan 25, discharge slide 28, control display243 and control keypad 242. The same view is seen in FIG. 2, with theaddition of discharge slide hood 29.

Turning now to FIGS. 3 and 4, a chassis 20 is shown supporting aconveyorized cooking surface 22. A lower heat source 46 positioned belowthe conveyorized cooking surface 22 and an upper heat source 146positioned above the conveyorized cooking surface 22. A discharge slide28 is adjacent and below the upper surface 23 of the conveyorizedcooking surface 22 to receive food products discharged from theconveyorized cooking surface 22 and directs such food products toholding pans.

Preferably conveyorized cooking surface 22 is suitable for broilingvarious food products and more preferably is suitable for flame broilingvarious food products. Conveyorized cooking surface 22 may be sized toreceive multiple rows of similar food products to facilitate batchcooking of those food products. Conveyorized cooking surface 22preferably remains stationary during cooking and only advances the foodproduct once the cooking or broiling process is completed. Upondischarge of the food product from the conveyorized cooking surface 22the conveyorized cooking surface 22 stops movement until the completionof the cooking process for the next batch of food products.

In another embodiment conveyorized cooking surface 22 remains stationaryduring insertion of the food products, and after insertion is adjusted,forward or backward, in order to facilitate best alignment of heatingelements to food product. This alignment will both facilitate uniformcooking and increase thermal efficiency. In this embodiment, alignmentis facilitated by a control mechanism as further described below.Preferably, in this embodiment, after initial lateral movement iscomplete, the conveyorized cooking surface remains stationary duringcooking and only advances the food product once the cooking or broilingprocess is completed. Upon discharge of the food product from theconveyorized cooking surface 22 the conveyorized cooking surface 22stops movement until the completion of the cooking process for the nextbatch of food products.

In yet another embodiment conveyorized cooking surface 22 remainsstationary during insertion of the food products, and after insertion isreciprocated during the cooking process in order to facilitate a moreuniform cooking of the food products. In this embodiment, reciprocationis facilitated by a control mechanism as further described below. Uponcompletion of the cooking cycle, the reciprocation is stopped.Subsequently, the conveyorized cooking surface advances the foodproduct, discharging it once the cooking or broiling process iscompleted. Upon discharge of the food product from the conveyorizedcooking surface 22 the conveyorized cooking surface 22 stops movementuntil the completion of the next batch of food products.

Lower heat source 46 is preferably a gas burner for flame broiling foodproducts but may also include other suitable means for broiling productsknown in the art, such as electric heating elements. Lower heat source46 is preferably arranged to radiate thermal energy directly to the foodproducts positioned on conveyorized cooking surface 22 so as touniformly broil the various food products without creating hot spots,cold spots, uneven charring or inconsistency between individual foodproducts of a particular batch. In one embodiment, a plurality ofelongated gas burners extend along the length of the broiler, arearranged in parallel, and are disposed underneath conveyorized cookingsurface 22. In another embodiment, only one lower burner is disposedunderneath conveyorized cooking surface 22. As the skilled artisan willappreciate, various types of different burners can be used including, byway of example and not limitation, atmospheric-type burners, powerassist type burners, induced draft burners, primary air induced burnersor premix burners.

As seen in FIG. 4, a flame arrestor 30 may be incorporated between theconveyorized cooking surface 22 and the lower heat source 46. Chassis 20may incorporate drawer receivers 32, tray supports, tabs or othersupport mechanisms to support flame arrestor 30. The flame arrestorfurther protects the food products from flame flare-ups resulting fromgrease, juices, and other renderings coming from the food products asthey cook and falling onto the lower heat source 46. Flame arrestor 30is preferably similar to the flame arrestor disclosed in U.S. Pat. No.5,727,451, incorporated herein by reference, and comprises a pluralityof perforated sheets of low thermal mass and relatively thinconstruction, and having an open area between approximately 25% and 75%of the total sheet area. The perforated sheets are positioned below theareas of conveyorized cooking surface 22 intended to receive batches offood products. As fat is rendered from the broiling food product, itfalls to the perforated sheet to be vaporized and quickly and cleanlybum prior to pyrolization.

The upper heat source 146 preferably directly radiates infrared (IR)energy to the food products according to a predetermined cycleassociated with a particular food product. By cycling the intensity ofthe IR emissions from upper heat source 146, exact cooking profiles canbe established to quickly adapt the automatic broiler between batches ofvarious food products, such as beef patties and chicken cutlets. Thecyclic IR emissions of upper heat source 146 may vary from an on-offcycle to a cycle of low intensity interrupted by periods of highintensity IR emissions or a cycle of high intensity IR emissionsinterrupted by periods of low intensity IR emissions, or any combinationthereof. Such cycles and their duration are ideally optimized for theparticular type of food product and batch size to be broiled in theautomatic broiler 10, thereby establishing the cooking profile of thedesired food product.

Upper heat source 146 is most preferably arranged to include two or morelongitudinal IR emitting heating elements arranged parallel to eachother, but could include a single IR emitting heating element. Theheating elements 157 preferably extend between side panels 14 and 15 andare disposed above conveyorized cooking surface 22. The preferabledistance between the heat elements and the conveyorized cooking surface22 is in the range of 2-6 inches, most preferably 3 inches. IR emittingheating elements 157 are spaced apart sufficiently to provide forventilation of combustion gases from lower heat source 46 and cookingfumes coming from the food products on conveyorized cooking surface 22,venting through passage 158. As the skilled artisan will appreciate,like the lower heat source, various types of different burners can beused with upper heat source 146 including, by way of example and notlimitation, atmospheric-type burners, power assist type burners, induceddraft burners, primary air induced burners or premix burners. Also likethe lower heat source, the upper heat source may be electric.

As seen in FIG. 5, to further increase efficiencies, the automaticbroiler 10 may be enclosed by an insulated housing 12 comprising a frontpanel 13, a right side panel 14, a left side panel 15, a top panel 16, abottom panel 17, and a back panel 18. The combination of theaforementioned panels creates a closed or semi-closed environment,greatly reducing thermal losses to the surrounding environment andproviding for greater control of temperatures at the cooking surface.Enclosing the automatic broiler also helps control the kitchentemperature by preventing heat from escaping from the broiler to thekitchen environment.

In a preferred embodiment front panel 13 includes a first opening (loadopening) 19 through which batches of the food product are loaded ontothe conveyorized cooking surface 22. Left side panel 15 also preferablyincludes a second opening (discharge opening) 20, best seen in FIG. 1,through which the batches of food products are discharged from theconveyorized cooking surface 22 to discharge slide 28. It should benoted that first opening 19 may also be incorporated into the left sidepanel 15, right side panel 14 or the back panel 18. In the embodimentdepicted in FIGS. 2-4 the front panel 13 is configured to receivedoor/loader assembly 60 such that when door loader assembly 60 is openedbatches of food product may be loaded onto the conveyorized cookingsurface 22 and when door assembly 60 is closed front panel 13substantially prevents the loss of thermal energy through first opening19.

In general, the door/loader assembly 60 has five generalcharacteristics. First, it allows for the quick and efficient insertionof a complete or partial batch of food products into the cookingchamber. Second, it locates the product quickly and accurately withinthe heating chamber. Third, it folds up and out of the way during thecooking process. Fourth, it seals the cooking chamber in order to ensureuniform heat distribution inside the cooking chamber and to increasethermal efficiencies. Fifth, it is removable without the aid of tools tofacilitate cleaning and repair.

As seen in FIGS. 5-7, in one embodiment, door/loader assembly 60preferably comprises sliding top shelf 61 and a bottom shelf 62. Slidingtop shelf 61 comprises sliding support tray 65 and stopper arm 63. Inoperation the door/loader assembly 60 is placed in a horizontal loadingposition. There, the operator places the batch of food product on to thesliding support tray 65. Once fully loaded, the operator slides supporttray 65 and stopper arm 63 until the entire support tray 65, and thusfood products, are inserted completely into the cooking chamber. Next,the sliding support tray 65 is removed while simultaneously holding thestopper arm 63 in place flush against panel 13, thus facilitating theremoval of the food products from the support tray 65 and onto theconveyor cooking surface 22. Finally, the stopper arm 63 slides back toits original position as shown in FIG. 4. Door/loader assembly 60 mountsto the front panel 13 at attachment points 64, which are configured toallow for the door/loader assembly to be manipulated from a horizontal,open loading position to a closed or partially closed cooking position.Additionally, the door/loader assembly may include a mechanism, such asslats or rails on support tray 65 for ensuring that the loaded batch offood products maintain proper positioning on the conveyorized cookingsurface.

It should also be noted that in another embodiment the door/loaderassembly of the present invention may include an automatic loadingmechanism whereby the loading of the food product is synchronized withthe cooking process and the discharge of the cooked product.

Right side panel 14 is preferably arranged to receive and house varioussupply, return and control lines to the automatic broiler, includinggas, electric, and control systems. Top panel 16 is preferably arrangedto provide for ventilation of combustion gases and cooking fumes. Backpanel 18 is preferably arranged to provide for easy removal tofacilitate maintenance and cleaning. Bottom panel 17 provides afoundation upon which chassis 20 rests.

As best seen in FIGS. 1, 4, 6-8, 10 and 11, left side panel 15 ispreferably arranged to receive inclined discharge slide 28 and renderingcollection bin 24 positioned below discharge slide 28. As previouslymentioned discharge slide 28 is preferably slightly below the dischargepoint 32 of conveyorized cooking surface 22. This arrangement allows forthe food product to tip downwardly toward the discharge slide allowinggrease, juices, or other renderings on the surface of the food productto spill onto the discharge slide and eventually collect in therenderings collection bin 24. Discharge slide 28 may includeperforations, slits, or grooves to allow the renderings to pass throughthe discharge slide 28 and into the collection bin 24. The exact slopeof discharge slide 28 may also be optimized to the particular foodproducts anticipated during operation to ensure proper discharge andremoval of renderings.

Removable food holding pan 25 is preferably positioned adjacent thelower side of the discharge slide 28 and is supported by pan supportingmember 27. Holding pan supporting member 27 may be a simple shelf or astandard mount compatible with holding pan 25. Preferably dischargeholding pan 25 is compatible with other kitchen appliances such asholding cabinets, steam cabinets, and product assembly cabinets tominimize the need to transfer the broiled food products between trays,as well as minimize exposure of the broiled food product to uncontrolledenvironmental conditions.

The automatic broiler 10 includes a control mechanism 200 forcontrolling operation of the automatic broiler 10. Preferably, thecontrol mechanism 200 has an operator input device, which in oneembodiment, comprises a keypad 242 and a display 243 to selectivelyallow the operator to interact with the control mechanism to inputvarious cooking profiles and/or to select various cooking profilesfacilitating control of the broiling environment, such as burner level,temperature, grilling time, and discharge speed. Alternatively theoperator input may include dials, switches and the like known to thosein the art. For example, rotatably mounted control dials mounted on thefront panel 13 and movable in a push-and-turn fashion to anyuser-selected positions may permit operator input to the controlmechanism 200. The control mechanism 200 may also include associatedindicator lights (not shown in FIGS. 1-14) and/or display 243 to informan operator of the selected cooking profile, the status of the automaticbroiler, and the condition of the food product within the automaticbroiler.

FIG. 15 illustrates a preferred embodiment of the control unit 200comprising a program key set operator input device 502, a multi-digitalpha-numeric display device 504, and a plurality of product keys 506.Additionally, a plurality of multi-colored information indicator lights508 correspond to and are adjacent to, or incorporated with, the productkeys 506.

In a preferred embodiment, upon initial activation of the broiler, thecontrol unit 200 senses the temperature inside the broiler cavity,compares that temperature to the pre-heat set temperature, and initiatesone of two pre-heat cycles. The pre-heat set temperature is preferablyset to 300° F. If measured broiler cavity temperature is lower than thepre-heat set temperature, then the control unit 200 activates the lowerheat source. In this scenario, the pre-heat cycle is complete when thecontroller 200 cycles off the lower heat source for the first time, plusan addition elapse of time, preferably 10 minutes. If measured broilercavity temperature is higher than the pre-heat set temperature, then thecontrol unit 200 continues to measure the cavity temperature, but doesnot activate the lower heat sources until the measured broiler cavitytemperature is lower than the pre-heat set temperature. In thisscenario, the pre-heat cycle is complete when the controller 200 cyclesoff the lower heat source for the first time.

In either case, control unit 200 controls the lower heat source, and anyrequired cycle, in order to achieve and maintain the temperature ofbroiler cavity. In a preferred embodiment, once the broiler cavityreaches a predetermined temperature, the control unit 200 activates theupper heat source. Upper heat source will remain active during thepre-heat cycle.

Additionally, during the pre-heat cycle, the control unit 200 preventsthe user from loading the broiler or starting a cooking cycle. Thedigital display device 504 will display a predetermined message and aLED indicator will indicating that the broiler should not be or cannotbe loaded during this cycle. In addition, the controller 200 willindicate a pre-heat status by illuminating indicator lights 508 in apredetermined selection of color and pattern. The digital display device504 will display a predetermined message indicating the broiler statusonce pre-heat cycle is complete. In a preferred embodiment, the broilercontrol unit 200 may be programmed during the pre-heat cycle in order tomaximize efficiency. When the broiler satisfies a set of pre-establishedconditions signaling the completion of the pre heat phase, such as thosedescribed above, the pre-heat cycle is complete and controller initiatesthe next cycle, an idle cycle.

Once, pre-heating is complete, the control system will maintain thebroiler in a ready position, or idle cycle. During the idle cycle, thecontroller 200 maintains the broiler cavity at a set temperature, theidle set temperature. In a preferred embodiment, the idle settemperature is the same as the pre-heat set temperature. Once thecontroller 200 initiates the idle cycle, the lower heat source 46 willshut off, if not already off, while the upper heat source 146 remainsactivated. In this idle cycle, the controller 200 monitors the broilercavity temperature. If the oven cools to a programmed lower temperaturelimit, the lower heat source 46 will cycle on and off to maintain thetemperature cavity at the idle set temperature. Oven status in the idlecycle will be indicated by illuminating indicator lights 508 in apredetermined selection of color and pattern, such as “READY” or “RDY,”different from that of the pre heat cycle.

From the idle cycle, the user can enter the cook cycle. During thecooking cycle, the controller 200 will cycle the upper heat source 146through a pre-defined profile and will control the cavity temperature bycycling the lower heat source 46 on and off. Upon completion of the cookcycle, the controller 200 activates the conveyorized cooking surface inorder to unload the cooked product. In a preferred embodiment, thecontroller 200 will activate an audible alarm upon completion of thecook cycle.

Selecting a desired cooking profile for a cook cycle is accomplished bypressing the desired product key 506. Operator choice is confirmed bythe illumination of the corresponding indicator light 508 in apredetermined color while the remaining indicator lights remain unlit.As the broiler is executing the pre-programmed cooking profile, theindicator light corresponding to the selected cooking profile willindicate the broiler's cooking status by illuminating in a predeterminedfashion, such as by flashing. Additionally, the display device willalternatingly display a predetermined message corresponding to thecooking profile chosen, and the remaining time required for the broilerto complete the cooking cycle. Completion of the cooking cycle isindicated by the countdown times on the display device 504 indicatingzero time remaining. An audible alarm will sound at the completion ofthe cooking cycle. Upon completion of the cooking cycle, theconveyorized cooking surface 22 will index a predetermined distance tounload the cooked food product. During the unload procedure, the displaydevice 504 will continue to indicate zero time remaining. Concurrently,the indicator light 508 associated with the selected cooking cycle willremain illuminated but in a distinctive pattern to differentiate betweenthe cooking cycle and the unload procedure. All other indicator lights508 will remain unlit. When the unload procedure is complete, indicatedby the completion of the index of the conveyorized cooking surface 22,the broiler assumes an idle status with appropriate displays.

In preferred embodiments, the control unit or mechanism 200 has threemain, programmable functions. First, the control unit 200 acts tocontrol the cooking profile for a particular product—the recipefunction. As described in more detail below, the cooking profileconsists of a regular or irregular sequence of upper heat sourceon-times and off-times. Second, the control unit 200 acts to control theunderlying system parameters. Third, the control unit 200 keeps track ofstatistical data.

With respect to the second programmable function, the control unit 200acts to control the underlying system parameters. In a preferredembodiment, the control unit controls the following: (1) IdleTemperature Parameter; (2) Offset Parameter; (3) ° F. or ° C. Parameter;(4) Chain Drive Time Parameter; (5) Over Temperature Alarm; (6) UnderTemperature Alarm; (7) Temperature Hysterisis; (8) Audiblealarm/Disable; and (9) Preheat IR Temperature.

The Idle Temperature Parameter is the set-point temperature for thebroiler during the preheat and idle cycles. Preferably, the temperaturewill be from 500 to 900° F., most preferably 680° F.

The Offset Parameter specifies a difference between the measuredtemperature and the displayed temperature. A positive offset parametermeans that the displayed temperature will be below the measuredtemperature by the offset parameter. A negative offset parameter meansthat the displayed temperature will be above the measured temperature bythe offset parameter. Preferably, the offset parameter will be setbetween −100 to +100° F., most preferably 0° F.

° F. or ° C. Parameter acts to change the temperature displayed betweenFahrenheit (F) and Celsius (C). Preferably, the default on thisparameter is Fahrenheit (F).

The Chain Drive Time Parameter defines the amount of time required todrive the chain to the conveyorized cooking surface a set amount,preferably half a complete rotation. Preferably, this parameter is setbetween 1 to 10 seconds, most preferably 6 seconds.

The Over Temperature Alarm parameter is the temperature above theset-point at which an over temperature alarm will occur. Preferably,this is set between 0 to 200° F., most preferably 200° F.

The Under Temperature Alarm parameter is the temperature below theset-point at which an under temperature alarm will occur. Preferably,this is set to between 0 to 200° F., most preferably 100° F.

The control will have an ON-Off type control. The control will cycle thetemperature output off at the set point temperature and will cycle itback on at a set number of degrees below the set point temperature. Thatset number of degrees, preferably 10° F., is defined as the TemperatureHysterisis. In a preferred embodiment, it will be set between 2 to 50°F., most preferably 2° F.

The Audible alarm/Disable allows the controller the ability to turn offthe audible alarm. With the buzzer turned off, the buzzer will stillsound for temperature sensor and ignition faults.

The Preheat IR Temperature is the temperature at which the IR burnercomes on during the Preheat cycle. Preferably, this will be set between301 to 900° F., most preferably 500° F.

With respect to the third programmable function, the control unit 200keeps track of statistical data. In a preferred embodiment, the controlunit 200 keeps track of the following:

-   -   Product Counts—Keeps track of the number of times that a product        has been run.    -   Run Time—Keeps track of the number of hours that the broiler has        been under power.    -   IR Ignition Attempts—Keeps track of the number of times that the        control supplies an output signal for the IR burners.    -   IR Initialization Failures—Keeps track of the number of times        that the control has detected a difference in the output and        input signals for the IR burners during the pre-heating cycle.    -   IR Failures During Cook—Keeps track of the number of times that        the control has detected a difference in the output and input        signals for the IR burners during the cooking cycle.    -   IR Failures During all Other Modes—Keeps track of the number of        times that the control has detected a difference in the output        and input signals for the IR burners during periods not covered        in IR Initialization Failures and IR Failures During Cook.    -   IR Gas Lockout Failures—Keeps track of the number of times that        the control has had a GAS fault related to the IR burners.    -   Lower Burner Ignition Attempts—Keeps track of the number of        times that the control supplies an output signal for the lower        burners.    -   Lower Burner Initialization Failures (“LbIf”)—Keeps track of the        number of times that the control has detected a difference in        the output and input signals for the lower burners during the        pre-heating cycle.    -   Lower Burner Failures During Cook (“LbCf”)—Keeps track of the        number of times that the control has detected a difference in        the output and input signals for the lower burners during the        cooking cycle.    -   Lower Burner Failures All Other Modes—Keeps track of the number        of times that the control has detected a difference in the        output and input signals for the lower burners during periods        not covered in LbIf and LbCf.    -   Lower Burner Gas Lockout Failures-Keeps track of the number of        times that the control has had a GAS fault related to the Lower        burner.

In a preferred embodiment, the control unit 200 is designed to detectvarious broiler function faults and provides the ability to diagnose andcorrect these faults. For example, the control unit 200 preferablydetects temperature faults, temperature sensor faults, and ignitionfaults. When the controller detects such faults, the display will show aunique fault identifier. The faults preferably include four maincategories.

The first is an over temperature fault. An over temperature fault occurswhen the control unit senses that the measured temperature is a setnumber of degrees above the idle set temperature for a set number ofcontinuous seconds. Preferably, this temperature is set to 100° F. abovethe idle set temperature and the set number of seconds is set to 30.Preferably, this fault will not be checked during the cook cycle. In apreferred embodiment, when this condition is detected: (1) the displaywill show “HI” or a similar unique fault indicator; (2) the control willallow the user to load or start a cook cycle; and (3) the lower burneroutput will stay off until the measured temperature is reduced to theIdle set point or a cook is initiated. Preferably, this fault willself-clear when the temperature is reduced.

The second is an under temperature fault. An under temperature faultoccurs when the control senses that the unit is a set number of degreesthan the idle set temperature for a set number of continuous seconds,preferably 30. Preferably, this fault will be checked during idle andcook cycles. In a preferred embodiment, when this condition is detectedduring the idle mode: (1) the display will show “LO” or a similar uniquefault indicator and (2) the control will not allow the user to load orstart a cook cycle. This fault will self-clear when the temperature isincreased. In a preferred embodiment, when this condition is detectedduring the cook cycle the control will continue cooking normally andthen sound an alarm at the end of the cook. Preferably, this alarm willconsist of an audible and a visible alarm. This alarm will continue pastthe end of the cook and chain rotation and will need to be cancelled bythe operator by pressing any key.

The third is a sensor failure. A sensor failure occurs when the controlsenses a short circuit or open circuit in the sensor circuit.Preferably, the control will have a set delay, most preferably 10seconds, before it indicates or reacts to a probe error. When thiscondition is detected the display will show “PROB” or a similar uniquefault indicator and an alarm will sound. The upper and lower gas valveoutputs will be shut down unless the unit is in the middle of a cookcycle. If the unit is in the middle of a cook cycle, the control willcontinue cooking normally and then sound an alarm at the end of the cookcycle.

The fourth is an ignition fault. Here, the control will compare an inputsignal from the ignition control module to the corresponding ignitioncontrol output. With respect to an ignition fault, if the broiler is inthe pre-heat cycle, the control will look for a difference in either theIR or lower signals that last for more than a set time, preferably 15continuous seconds. On the first occurrence the control will cycle theburner output that has the fault (i.e. IR or lower burner output) bycycling output off for a set time, preferably 4 seconds, and then backon. If the control detects a second occurrence on the same burner within5 minutes of the first occurrence the control will: (1) sound an alarmand (2) shut down both gas valve outputs. If the broiler is in the idlemode, the control will look for a difference in either the IR or lowersignals that last for more than at set time, preferably 15 continuousseconds. On the first occurrence the control will cycle the burneroutput that has the fault (i.e. IR or lower burner output) off for a settime, preferably 4 seconds, and then back on. If the control detects asecond occurrence on the same burner within a set time, preferably 5minutes, of the first occurrence the control will: (1) sound an alarmand (2) shut down the gas valve output that is related to the faultcondition. If the broiler is in a cook cycle, when the control detects adifference in either the upper or lower signals the control willimmediately stop the cook time countdown whenever there is a differencein these signals (ignoring the delay for ignition moduleinitialization). The control will allow the time countdown to be stoppedfor a maximum of 5 minutes. After 5 minutes the control will proceedwith the countdown normally. The control will continue cooking normallyand then sound an alarm at the end of the cook.

The control mechanism 200 is used to input and select a desired cookingprofile and control the operation and environment of the automaticbroiler. The control mechanism 200 is operable to vary the amount ofradiant heat as needed to properly cook, and preferably broil, thedesired food product. In one embodiment, the control mechanism comprisessuitable timer and duty cycle controls to control the length of theduty-cycle of the upper heat source 146, the term “duty cycle” meaningthe ratio of upper heat source on-time (activated) to upper heat sourceon-time plus off-time (deactivated). Additionally, the control mechanism200 controls the operation and movement of the conveyor cooking surface23, providing control for any initial forward or backward movement tofacilitate alignment of the food products with the heating elementsand/or the final operation and thus discharge of the cooked foodproducts. The control mechanism 200 uses a suitable microprocessor andappropriate software to control the conveyorized cooking surface as wellas relays 248 (FIG. 13) that activate the upper heat sources 146. Upperheat sources will be activated and deactivated in different ways,depending on their configuration. As the skilled artisan would readilyappreciate, electric heating elements could for example, be activatedand deactivated by controlling the power to the heating circuit. Gasburners could be activated or deactivated by controlling electronicsolenoid valves. In accordance with the present invention, other heatingelements may be controlled in other ways known in the art.

FIG. 12 illustrates an embodiment in which the heat source 146 issuccessively activated and deactivated in a controlled, periodicsequence or duty cycle, indicated at G, to vary the amount of radiantheat as needed to properly cook, and, preferably broil, the desired foodproduct. In this particular embodiment, each duty cycle G comprises aheating interval E during which time the heat source 146 is activatedfollowed by interval F during which time the heat source is deactivated.The intensity and duration of the periodic cycles of infrared emissionfrom the upper heat source 146, are determined empirically and willdepend on the desired batch of food product to be broiled.

In other embodiments, the periodic duty cycle function is replaced witha pre-programmed irregular sequence of upper heat source on-times andoff-times. FIG. 13 is an example of such a pre-programmed irregularsequence. FIG. 13 illustrates an embodiment in which the heat source 146is successively activated and deactivated in a controlled,pre-programmed irregular sequence to vary the amount of radiant heat asneeded to properly cook, and preferably broil, the desired food product.In this particular embodiment, A and C represent length of on time forthe top IR heating element or elements, while B and D represent lengthof off time for the top IR heating element or elements. E is the sum ofall on and off times in the cooking program. A, B, C, and D can beprogrammed to any length of time and additional off or on periods can beadded. In these embodiments, an irregular sequence, as opposed to theperiodic duty cycle, is used to vary the amount of radiant heat asneeded to properly cook, and preferably broil, the desired food product.The intensity and duration of the irregular sequence of infraredemission from the upper heat source 146, is determined empirically andwill depend on the desired batch of food product to be broiled.

FIG. 13 is a simplified schematic of a portion of one embodiment of anoven control circuit 240 that is controlled by the control mechanism200. The circuit 240 operates upper heat source 146 of the automaticbroiler 10. In the embodiment shown in FIG. 13, the circuit 240 operatessolenoids 246. When energized, solenoids 246 open a gas flow valve thuscontrolling the flow of gas to the upper heat source. Other embodimentscould use other heating control mechanisms well known in the art, suchas energizing conventional relays. Using a keypad 242 and a display 243,or other suitable operator input device, the control mechanism 200 canbe programmed to control the heat upper heat sources 146 according tothe selected cooking profile for the desired food product. Similarly,control mechanism 200 may also control the lower heat source 46 and theconveyorized cooking surface 22, although in a preferred embodiment,lower heat source provides a continuous uniform heat to the conveyorizedcooking surface 22 rather than cycling through duty cycles. In oneembodiment the conveyorized cooking surface 22 remains motionless duringloading and broiling and only advances to discharge the batch of foodproduct after the food product has completed cooking. In anotherembodiment the conveyorized cooking surface 22 may be initiallylaterally adjusted (forward or backward) to facilitate product cookinguniformity and prevent thermal inefficiency by ensuring the most directIR heat is applied to the food products.

In use, a preferred embodiment of the present invention stores a cookingprofile, or recipe, in the automatic control unit 200 which establishescooking temperatures, thermal output for the lower heating source 46 andthe upper heat source 146, the period, intensity and duration of thecycles of infrared emission from the upper heat source 146, and theactivation of the conveyorized cooking surface 22. An operator selects astored cooking profile depending on the desired batch of food product tobe broiled. The food product is then positioned on the door/loaderassembly 60 and door/loader assembly 60 is loaded through the firstopening 19 and the batch of food product is deposited on theconveyorized cooking surface. Preferably, the conveyorized cookingsurface is stationary during loading and cooking. The operator thenremoves door/loader assembly 60 from the first opening 19 and placesdoor/loader assembly in the closed position to improve thermalefficiency of the broiler and prevent thermal losses through frontopening 19.

Additionally, the automatic control unit 200 in a preferred embodimentcan comprise an interface to allow cooking profiles and operatingsoftware to be downloaded to the control unit 200 from an externalsource. A preferred embodiment may comprise a storage device to maintainoperating data, electromechanical data, and fault information foruploading through the same interface.

Preferably lower heat source 46 provides continuous heat to the batch offood-product on the conveyorized cooking surface 22. Alternatively, theintensity of the heat emitted from lower heat source 46 may be variedaccording to the particular food product to be broiled and the size ofthe batch. Upper heat source 146, however, preferably pulses or cyclesthrough periods of high intensity infrared emission and low intensityinfrared emission depending on the selected cooking profile. The cyclicIR emissions of upper heat source 146 may vary from an on-off cycle to acycle of low intensity interrupted by periods of high intensity IRemissions or a cycle of high intensity IR emissions interrupted byperiods of low intensity IR emissions, or any combination thereof. Suchcycles and their duration are ideally optimized for the particular typeof food product and batch size to be broiled in the automatic broiler10, thereby establishing the cooking profile of the desired foodproduct.

When the period of cycles from the upper heat source has finished thebatch of food products are completely cooked and ready for discharge.The conveyorized cooking surface then activates and advances the batchof food product toward discharge end 32. The food product upon reachingdischarge end 32 is tipped downwardly toward the discharge slide 28allowing any grease, juices, or other renderings on the surface of thefood product to spill onto the discharge slide 28 and eventually collectin the renderings collection bin 24. The food product then slides downthe discharge slide and into the holding pan 25.

Although the invention has been shown and described above with referenceto certain preferred embodiments, it will be readily appreciated bythose of ordinary skill in the art that various changes andmodifications may be made therein, without departing from the spirit andscope of he invention. It is intended that the claims be interpreted asincluding the foregoing as well as various other such changes andmodifications.

1. An automatic broiler for batch cooking comprising: a conveyorizedcooking surface; a lower heat source positioned below the conveyorizedcooking surface; an upper heat source positioned above the conveyorizedcooking surface; a control means for selectively storing multiplecooking profiles of food products; regulating the thermal output of theupper and lower heat sources depending on the cooking profile selected;pulsing the thermal output of the upper heat source independently fromthe lower heat source to provide the appropriate thermal outputdepending on the cooking profile selected; timing the thermal output ofthe upper and lower heat sources depending on the cooking profileselected; and discharging the batch of food products according to thecooking profile selected by actuating the conveyorized cooking surface.2. The automatic broiler of claim 1 wherein said upper heat source isarranged in at least two longitudinal heating elements with a ventinterspaced between each row of heating elements to provide forventilation of gases.
 3. The automatic broiler of claim 1 wherein saidlower heat source has an open flame.
 4. The automatic broiler of claim 3wherein a flame arrestor is above said lower heat source but below theconveyorized cooking surface.
 5. The automatic broiler of claim 3wherein said lower heat source comprises at least two longitudinalheating elements.
 6. The automatic broiler of claim 1 furthercomprising: an insulated housing surrounding the conveyorized cookingsurface and heat sources; a load opening in the insulated housing forloading batches of food product onto the conveyorized cooking surface; adischarge opening in the insulated housing for discharging batches offood product from the conveyorized cooking surface at the completion ofthe selected cooking profile.
 7. The automatic broiler of claim Ifurther comprising: an insulated housing surrounding the conveyorizedcooking surface and heat sources, said insulated housing furthercomprising; an insulated front wall having an opening for loadingbatches of food product onto the conveyorized cooking surface; aninsulated back wall; an insulated bottom wall wherein the bottom wall isadapted to receive renderings from the broiled food products on theconveyorized cooking surface; an insulated top surface adapted providefor ventilation of gases; and insulated side walls wherein at least oneof the side walls incorporates an opening for discharging batches offood product from the conveyorized cooking surface at the completion ofthe selected cooking profile.
 8. The automatic broiler of claim 6further comprising an integrated door/loader assembly for automaticallyloading batches of food product onto the conveyorized cooking surfacethrough an opening in the insulated housing wherein the door/loaderassembly minimizes thermal losses from the insulated housing after thebatch of food product has been loaded.
 9. The automatic broiler of claim8 further comprising a food product placement means for ensuring thatthe loaded batch of food products maintain proper positioning on theconveyorized cooking surface.
 10. The automatic broiler of claim 6wherein the discharge opening in the insulated housing for dischargingbatches of food product includes a discharge slide and a collecting panfor collecting the batch of food product after discharge from thecontinuous cooking surface.
 11. A method of automatically cookingbatches of food products comprising: loading a batch of food productsonto a conveyorized cooking surface; cooking the food products in astationary position without moving the conveyorized cooking surface;activating the conveyorized cooking surface upon completion of thecooking process, such that the food products are discharged.
 12. Amethod of automatically cooking batches of food products comprising:loading a batch of food products onto a conveyorized cooking surface;actuating the conveyorized cooking surface to optimize the cookingposition of the food products cooking the food products in a stationaryposition without moving the conveyorized cooking surface; uponcompletion of the cooking process, activating the conveyorized cookingsurface such that the food products are discharged.
 13. A method ofautomatically broiling batches of food products comprising: storing aselectable cooking profile in an automatic control means; selecting acooking profile; loading a batch of food products onto a conveyorizedcooking surface; heating the batch of food products with a lower heatsource that is below the conveyorized cooking surface; heating the batchof food product with a variable controllably pulsating upper heat sourcethat is above the conveyorized cooking surface; controlling the thermaloutput of the upper and lower heat sources with the automatic controlmeans depending on the cooking profile selected; and discharging thebatch of food products from the conveyorized cooking surface accordingto the cooking profile selected.
 14. The method of claim 13 wherein thestep of loading the batch of food products is done with an automaticloader positioner.
 15. The method of automatically broiling batches offood products of claim 13 wherein the lower heat source comprises atleast two parallel longitudinal gas flame burners.
 16. The method ofautomatically broiling batches of food products of claim 13 wherein thepulsing upper heat source further comprises at least two longitudinalheating elements with a vent interspaced between each heating elementsto provide for ventilation of gases.
 17. The method of automaticallybroiling batches of food products of claim 13 wherein a flame arrestoris positioned below the conveyorized cooking surface and above the lowerheat source.
 18. The method of automatically broiling batches of foodproducts of claim 13 wherein the step of discharging the food productfurther comprises discharging the food product from the conveyorizedcooking surface onto a slide and removing an appreciable amount ofexcess renderings from the food product before the food product iscollected in a holding pan.
 19. The method of automatically broilingbatches of food products of claim 13 wherein the step of loading thebatch of food products further comprises loading the food productsthrough an opening in an insulated housing, the insulated housingsurrounding the conveyorized cooking surface and a lower heat source anda top heat source.
 20. The method of automatically broiling batches offood products of claim 19 wherein the opening includes a door loadingassembly.
 21. The method of automatically broiling batches of foodproducts of claim 19 wherein the insulated housing further comprises; aninsulated front wall having a first opening for loading batches of foodproduct onto the conveyorized cooking surface; an insulated back wall;an insulated bottom wall wherein the bottom wall is adapted to receive arendering collection bin for collecting renderings; an insulated topsurface adapted provide for ventilation of gases; and insulated sidewalls wherein at least one of the side walls incorporates a secondopening for discharging batches of food product from the conveyorizedcooking surface at the completion of the selected cooking profile. 22.The automatic broiler of claim 1 in which the control means includes aselection of predetermined cooking profiles for selected food products23. The automatic broiler of claim 1 in which the control means canactivate the upper and lower heating elements independently.
 24. Theautomatic broiler of claim 1 in which the control means provides anoutput signal indicating broiler status.
 25. The automatic broiler ofclaim 1 in which the control means collects and stores statistical dataon broiler performance and operating conditions.